1. Technical Field
The present invention relates generally to logical control circuits, and more particularly to a dynamic-static logical control element for signaling an interval between the end of a control signal and the beginning of a logical evaluation.
2. Description of the Related Art
Dynamic logic circuits are well known in field of digital circuits. Dynamic logic is used to decrease device count and increase speed in large-scale circuits such as very-large-scale-integration (VLSI) circuits. Often referred to as “domino” logic circuits due to their typically cascaded arrangement, clocked dynamic logic performs evaluation and storage functions in microprocessors, memories and other digital devices.
Dynamic logic circuits operate in a two-phase manner: clock signals are used to precharge nodes in the circuits to known values, typically at or near one of the power supply rails. Then, when the precharge clock changes state, an evaluation is performed by discharging the precharged nodes with ladders or “trees” of transistors connected in parallel-series arrangement to the opposite power supply rail. In a typical gate, with an inverter coupling a summing node to the output and N-channel transistor ladders used to pull down the summing node from a logical high level precharge state, each ladder combines its inputs in a logical AND function (as all transistors in a ladder must be on for the ladder to pull down the summing node), while the parallel connected ladders are combined in a logical OR function, as any activated ladder will pull down the summing node, resulting in a logical high level at the output of the dynamic logic gate.
In certain topologies and particular gate arrangements, static logic can be combined with dynamic logic to reduce circuit size, increase speed or provide other topological benefits.
Therefore, it is always desirable to combine static and dynamic functionality in a logic circuit when advantageous to reduce complexity or improve operation and thus provide additional logic gates and circuit arrangements that add logical building blocks to the state of the art.